These are the horrific scenes witnessed on a Dublin Bus this week when a woman looked to be violently assaulted.

The recording, filmed by a passerby outside the vehicle, sees the woman standing in the middle of the top deck when the man approaches her aggressively.

He then begins repeatedly punching her, forcing her up against the window as she tries to shield herself from the blows.

The video has yet to be verified, but a spokeswoman for Dublin Bus confirmed there had been an incident on board the No 40 near Old Kilmainham Village at around 10.15pm on Wednesday.

She said: "Our driver contacted our Central Control Team immediately, who then contacted emergency services. An ambulance then arrived at the scene, and the woman was brought to hospital.

"There were 18 people onboard the bus at the time. Garda have requested CCTV footage from the bus, and normal procedure in cases like that is to supply it to them and co-operate fully with the investigation."

It's believed that a second man was injured in the incident after trying to intervene.

A Garda spokesman said: "Gardai in Kilmainham received a complaint on Thursday from a man regarding an assault the previous night.

"He says he was approached and attacked on a Dublin Bus. He went to hospital afterwards himself as he had received some injuries.

"Gardai are investigating and will look at CCTV footage from Dublin Bus. We are also appealing for any member of the public with information to come forward."

The number 40 bus operates between Finglas Village and the Liffey Valley Shopping Centre.